DAM50 Extracellular Amplifier

Item#: SYS-DAM50

A family of very low noise battery-operated amplifiers

  • Battery powered to eliminate line noise
  • High pass and low pass filtering
  • Single ended or differential operation
  • DC/AC amplification
  • Variable output positioning
  • Constructed of high quality components to ensure minimal intrinsic (shot) noise
  • Portable
  • Rack mountable

Unit Price: 1139.00


For pricing, Customers outside of the US and Canada, please Contact your distributor

See the current Spec Sheet.

See what you need to know before you buy an amplifier.


  • Very low internal noise
  • Ultra quiet DC power supply ­— no AC required
  • Intrinsic low susceptibility to ground loops
  • Small footprint
  • Cost-effective
  • Electrostatic Discharge Protection!


  • Amplifying biopotentials from metal electrodes
  • Brain slice field stimulation
  • EAG (Electroantennogram)
  • ERG (Electroretinogram)

WPI’s DAM series amplifier’s are well known as a standard of the industry for extracellular potential amplification. These battery powered bio-amplifiers are designed with a compact chassis profile that enables you locate the unit closer to the preparation and thereby minimize long lead lengths which contribute to noise. Each amplifier is equipped with selectable high and low filters, and a position control to offset galvanic potentials which may develop during recording.

DAM series amplifiers can be used as stand-alone units on any tabletop or use optional clamp-mounting hardware to locate them conveniently within the work area. Alternatively, a pair of amplifiers can be mounted into a standard equipment rack with a rack mount kit (3484). A variety of hook up accessories are available to configure your application.

Reducing Noise with Differential Amplification

Differential amplification is of great importance in bioelectric recording to reduce the ever present effect of noise interference from power line induction. A well designed differential amplifier will significantly diminish power line (mains) noise. It is most essential that the preparation be connected with an electrode to a good electrical ground as well as to the grounding wire of the DAM50 itself. This should have the effect of greatly reducing electrostatically induced potential. In addition to the preparation ground, two differential input connections must be made via appropriate electrodes applied to the recording site so as to optimally record a bioelectric potential difference.

Feature Comparison Chart

  DAM50 DAM80
Input Mode AC/DC AC
Input Configuration Differential/Single Ended Differential
Gain Range 100-10,000 (AC)
10-1,000 (DC)
100 - 10,000 (AC)
High/Low Filters Yes Yes
Offset Position Control Yes Yes
Current Generator No Yes
Remote Active Headstage No Yes
Output Connection BNC 3.5 mm mini phone
Standard Input Connection unterminated wire Mini banana
Power Supply (2) 9V alkaline batteries (2) 9V alkaline batteries
INPUT IMPEDANCE 1012 Ω, common mode and differential
GAIN AC: 100x, 1000x, 10000x, DC: 10x, 100x, 1000x (DAM50)
AC MODE NOISE 0.4 μV RMS (2uV p-p) 0.1-100 Hz
AC MODE NOISE 2.6 μV RMS (10uV p-p) 1 Hz-10 kH
DC MODE NOISE (DAM50) (DAM50) 7.5uV RMS (30uV p-p) 3-10 kHz
BANDWIDTH FILTER SETTINGS:AC Mode Low frequency, 0.1, 1, 10, 300 Hz
BANDWIDTH FILTER SETTINGS: DC Mode(DAM50) High frequency, 0.1, 1, 3, 10 kHz
BATTERY TEST Audible tone
CALIBRATOR SIGNAL 10 Hz square wave
POSITION Approximately 250 mV
EXTERNAL COMMAND Input Voltage ±10 V commands
AC or DC current waveform ±50μA max. amplitude @ 200 KΩ
BATTERIES 2 x 9 V alkaline (included)
DIMENSIONS:DAM50 8 x 4 x 1.75 in. (20.3 x 10.2 x 4.4 cm)
SHIPPING WEIGHT 3.5 lb. (1.6 kg)

The following bandwidth charts for the DAM50 show the response of the amplifier when various filters and gains are used. For larger images, click on the thumbnails below. 

Bandwidth charts for the DAM50

GAINS: This chart shows the standard 3dB frequency cutoff at  maximum filter band pass.

The standard 3dB frequency

FILTERS: Various low pass and high pass filters were applied at the AC x1000 gain setting to show the bandwidth of and actual DAM50 amplifier.

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DAM80P Replacement Probe
3072 6 Replacement Modular Cables (DAM50)
3517 2 Optional Shielded modular Cables (DAM 50)
CBL102 3.5mm Phone plug to BNC Cable
2851 BNC-to-BNC Cable
2033 Black Insulated Mini-Banana Plug
2034 Red Insulated Mini-Banana Plug
2035 Uninsulated Mini-Banana Plug
2101 9V Alkaline Battery, each (2 required)
3484 Rack Mount Kit (for 2 DAM preamps)
3485 Ringstand Mounting Kit
5447 Electrode Adapter (DAM50)
5469 Metal Micro electrode Adaptor (DAM80) (mini banana plug to 0.031 in. socket)
5489 Adapter for Metal Microelectrod (DAM50)
13388 Adapter, mini-banana plug to 2mm socket
5371 Cable, Low noise (2mm pin to 2mm pin)
3578 Adapter Cable for Ag/AgCl pellets (2mm pin)
300102 Electrode Extension, 4"
3414 9V NiMH Battery
MEH7W-XX Microelectrode Holder, 1.0, 1.5 or 2.0 mm OD

DAM50 includes the 3517 (2 optional shielded modular cables)


Differential Applications for Metal Electrodes

The images below show two applications for metal electrodes. Click on the images to see a larger view. You may also see the schematics for the Application Examples.

This first example shows an EP1 silver/silver chloride electrode pellet soldered to the amplifier cable. This shows a differential configuration. The EP1 is suitable for use in a mouse cranial application. To do so, it needs an extension wire to connect it to the white-green GND junction on the DAM50 cable.






In this second example, a sealed RC1Ag/AgCl electrode pellet is wired to the amplifier cable. This also shows a differential configuration.



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